• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.227-230
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• 2010

본 논문은 디지털 케이불망에서 초고선명 TV(Ultra High Definition TV) 서비스를 위한 100Mbps급 1024-QAM 전송시스템 개발에 관하여 기술한다. 8K-UHD TV(해상도 7680x4320) 콘텐츠 전송을 위해서는 l개의 프로그램당 약 100-160Mbps의 대용량 데이터 전송률이 확보되어야 하며. 이러한 대용량 데이터 전송을 위해 타매체에 비해 상대적으로 전송채널 환경이 우수한 디지털 케이블망(HFC:Hybrid Fiber and Coaxial)을 이용한 대용량 실감데이터 전송기술에 대한 연구가 주목받고 있다. 본 논문에서는 이와 같은 UHD 실감콘텐즈 전송을 위하여, OpenCable(J.83 Annex B) 확장형 1024-QAM 송수신기술 및 방송망 채널본딩기법을 적용한 100Mbps급 송수신 기술개발에 대한 내용을 기술한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.96-97
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• 2010

다중 홉 중계기술은 차세대 무선통신을 위한 핵심 기술로 최근 전 세계적으로 활발히 연구되고 있으며, 셀 용량 증대, 셀영역 확장, 음영지역 축소 등의 장점으로 인하여, IEEE 802.11s, 802.15.4, 802.16j 등의 표준화에의 반영을 위한 논의가 활발히 진행되고 있다. 본 논문에서는 간섭신호가 존재하지 않는 이상적 네트워크 환경을 고려한 기존 연구의 한계를 극복하기 위해, 다중 간섭신호가 존재하는 레일레이(Rayleigh) 페이딩 채널에서 이중 홉(dual-hop) 복호후재전송(DF : decode-and-forward) 중계시스템의 시스템 모델을 제안하고, 모의실험을 통하여 불능확률 및 4진 직교 진폭 변조(4-QAM)를 위한 평균비트오율 (average bit error rate) 성능을 살펴본다.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.110-111
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• 2010

IPTV 서비스는 기존 단방향 지상파 TV보다 다양한 채널의 다양한 콘텐츠를 제공하므로 사용자가 빠르고 쉽게 원하는 콘텐츠를 찾기 위한 개인화 IPTV 사용자 인터페이스 개발이 요구되고 있다. 하지만 기존의 연구는 단방향 TV 서비스 인터페이스를 그대로 이용하거나 단순 카테고리 별로 분류된 정보 제공에 머물러 개인화된 인터페이스로는 아직 미흡하다. 본 논문에서는 협력적 여과, 내용기반 여과 등 기존 개인화 추천 기법을 이용하여 사용자가 원하는 정보를 빠르게 제공하고, 사용자의 편의성을 증대하는 SmarTVi 인터페이스와 개인화된 검색 결과를 제공하는 검색 모듈 SmarTVi-Search를 제안한다.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.65-71
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• 2010

In this study, a series of finite element analysis using LUSAS were performed in order to assess the quantitative effects of repair and retrofit of stringer in steel plate girder railway bridge with fatigue cracks. And cutoff types of end part of upper flange were considered as right-angled type and round-angled type. Also, as a method of repair and retrofit of fatigue cracks in stringer, perforation of stop-hole and installation of bracket were considered. From the analysis result, it was possible to assess the fatigue safety and fatigue life of stringer with fatigue cracks, and to estimate the stress intensity factor range in cut-off part of stringer using J-integral method. Also, according to the method of perforation of stop-hole and installation of bracket, it was possible to calculate the crack propagation life at the cut-off part of stringer.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.1
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• pp.66-72
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• 2016

The aim of this paper is to investigate the characteristics of the signal of local ice load acting on side shell in the bow part due to ice broken by an icebreaker in ice-covered waters. The Korean icebreaking research vessel "ARAON" voyaged to the Arctic Ocean during the summer of 2010, and measurements of local ice load were carried out using several strain gauges. In this study, the time history of measured signals was analyzed and the characteristic values including rising time and half-decaying time were presented using non-dimensional parameters.

• Photonics industry news
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• s.38
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• pp.24-29
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• 2007

CCTV 산업은 보안산업의 일종이며 종래에는 CCTV 카메라에서 찍은 영상정보를 아날로그 방식으로 VCR에 저장하여 사용하였으나, 테이프 교체의 불편함과 반복사용에 따른 화질의 열화 등 많은 문제점을 안고 있어 최근에는 DVR로 대체되고 있는 추세이다. 현재 국내시장에서 아날로그 VCR 대 DVR의 비율은 70:30 정도로 추정되고 있으며, 통신기술의 발전으로 인한 네트워크망 확대 및 인터넷의 급속한 보급으로 인해 DVR의 보급이 급속히 높아지고 있는데, J.P Freeman 보고서에 따르면, 세계 DVR 시장규모는 2002년 7억 2천만 달러에서 2005년도 24억 달러로 확대되어 연평균 47%의 고성장 하고 있다고 발표하였다. 그리고, DVR의 VCR 대체율 역시 2002년 13%에서 2005년 45%에 이른 것으로 보고 있으며, 앞으로 설치하거나 교체하는 시스템은 VCR 대신 DVR을 선택할 것을 예측할 경우 2010년에는 전체 VCR의 90% 이상이 DVR로 교체될 것으로 전망되고 있다.

• Research in Community and Public Health Nursing
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• v.21 no.1
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• pp.82-91
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• 2010

Purpose: The purpose of this study was to identify factors that influence medication adherence in patients with hypertension. Methods: One hundred sixty two patients with hypertension who visited the outpatient clinics of health centers in J City participated in the study. Data were collected through a questionnaire survey done from January 9 to February 25, 2008. To analyze the sample survey data, descriptive statistics, t-test, ANOVA, Scheffe's test, and multiple regression analysis were performed with SPSS/WIN 12.0. Results: Significant factors that affect medication adherence in patients with hypertension were autonomous motivation, competence, health status, and sex. These variables explained 24% of medication adherence (F=12.48, p<.001). Conclusion: The results indicate that in order to improve the medication adherence of patients with hypertension it is important to develop nursing programs that focus on autonomous motivation and competence and to give consideration to differences in health status and sex. Also further studies are needed to confirm autonomous motivation related to health behavior in patients with hypertension.

• Transactions of The Korea Fluid Power Systems Society
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• v.7 no.3
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• pp.20-27
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• 2010

A vehicle suspension system performs two functions, the ride quality and the stability, which conflict with each other. An active suspension system has an external energy source, from which energy is always supplied to the system for continuous control of vehicle motion. Therefore, an active suspension system can have even more improved performance. Some control laws have been proposed for active suspension system, but in this paper, an optimal variable structure control(VSC) is proposed. The VSC method is well suited for a class of nonlinear system and can address the robustness issues to constant modelling errors and disturbances. This paper develops an optimal VSC controller and compares its performance to those of a passive suspension system and an active suspension system with an optimal controller. The transient and frequency responses are analyzed respectively.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.252-257
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• 2010

SAR has pulse compression gain through the process including range and azimuth. Efficient jammers against the SAR with simulated elements are evaluated in the view of power and SAR image. In this paper, J/S is analysed for SAR with RF propagation equation firstly. Several jamming signals on SAR signal are made into SAR image through pulse compression process. Objective jamming performance is evaluated using euclidean distance.

• The Journal of the Korean dental association
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• v.48 no.10
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• pp.724-728
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• 2010

Accurate analysis of facial asymmetry prior to any orthognathic or orthodontic treatment plan is essential in ensuring good treatment result. Dental CBCT (Cone-beam Computed Tomography) provides as actual three-dimensional measurements of distance and angle without any radiographic magnification as medical CT provides, while its field of view is limited to the oral and maxillofacial area. CBCT is a useful tool for the diagnosis of facial asymmetry. The coordinates of facial landmarks are obtained from the 3D reconstruction software which enables the establishment of perpendicular planes and the identification of the landmarks. Then, the bilateral discrepancies of the landmarks are obtained as spherical polar coordinates which can show the amount of asymmetry and its direction. A method of 3D analysis of facial asymmetry using CBCT is introduced in this report.